The present invention relates to a method of controlling the setting of a machining coordinate system in a machine tool suitable for application when machining is being performed on a workpiece on both spindle stocks in a machine tool having two spindle stocks on which workpiece spindles are mounted facing each other.
A machine tool capable of executing a first routine of machining and a second routine of machining for each workpiece spindle successively in such a manner that spindle stocks having workpiece spindles provided facing each other are relatively free to move and drive in the Z axis direction and a workpiece is delivered between workpiece spindles, performing machining on a long sized workpiece without a center rest in such a manner that the long sized workpiece is rotated while being held between both workpiece spindles and performing machining successively on a bar shaped workpiece, a predetermined length of which is pulled out from one workpiece spindle at a time, has recently been proposed.
However, the manner of setting a machining coordinate system when machining a workpiece between workpiece spindles in a case where two spindle stocks are provided facing each other is important for proper machining, and development of such a control method is desired.
In consideration of the above, the object of this invention is to provide a method of controlling the setting of a machining coordinate system in a machine tool capable of performing machining in a workpiece in opposed spindle stocks smoothly.